In a background fuser unit that is used for an image forming apparatus, a fuser unit configured to fix a toner image on a sheet conveyed between a heating roller and a pressing belt has been known.
As the fuser unit, a fuser unit including a belt guide having an inner surface guide configured to guide an inner surface of the pressing belt and a restraining part configured to contact an end surface of the pressing belt and a pressing arm disposed at a outer side of the belt guide in a first direction of the pressing belt has been known.
In the fuser unit, the belt guide is fitted to a pressing stay with a gap, to which the pressing belt is wound, and the pressing arm is fitted to the pressing stay. A protrusion protruding outwards from the belt guide in the first direction is contacted to the pressing arm, so that the belt guide swings with respect to the pressing arm. Therefore, a fuser unit of which the pressing belt is bent and contacted to the restraining part to disperse the corresponding force has been known